This invention relates to couplings and, more particularly, relates to apparatus for quickly and releasably establishing a quick-connect, automatically locking fluid-tight coupling between hose sections or the like.
Apparatus has long been known for releasably interconnecting sections of tubular goods such as fire or oilfield hose or tubing into fluid-tight engagement, such apparatus including many variations of the familiar male-female threaded joint couplings. One obvious disadvantage of such couplings was the need for joints of separate male or female design, whereby only hose section with opposite couplings could be joined. Yet another disadvantage of such threaded couplings was the inordinate time and difficulty often experienced in making up the threaded joints by relative rotation of the couplings, such difficulties often being extremely crucial for example, in emergency fire ground situations. Spanner wrenches or the like were also frequently necessary to insure fluid-tight engagement. Moreover, the exposed threads were often subject to damage in the deleterious environment of fire scenes or oilfield applications by foreign substances clogging the threads, metal fatigue, cross-threading, or other damage.
For these and other reasons, couplings of a "quick-connect" variety were developed in the art which could establish a fluid-tight seal therebetween by means of only a partial relative rotation of the couplings about a common longitudinal axis. However, serious problems have been associated with such couplings of the quick-connect design.
For example, in some applications, the hose terminating in one of the couplings was not always aligned coaxially with the couplings themselves but rather was disposed at an angle thereto. When the hose was thereafter charged with pressure, the joint formed by the couplings frequently became disconnected and often in a violent fashion due to the rotational torque about the axis of the couplings. This, in turn, resulted many times in injury to surrounding personnel as well as causing dangerous conditions to exist due to the break in the pressurized lines, which often carried hazardous or high pressure materials. Moreover, no means were provided for establishing a quick-releasing automatically locking mechanism between the couplings.
Accordingly, a hydraulic coupling was long sought after which was of a quick-connect form yet provided a dependable foolproof and releasable locking engagement between the coupling members. Such a coupling design is provided in the present invention wherein a fluid pressure-tight seal may be effected between two such couplings, each of a mirror-image universal design. Each coupling is provided with a locking assembly which automatically locks the couplings together in a fluid-tight seal upon the rotational action required for make-up of a joint. The locking mechanisms are further automatically re-armed upon rotation in the opposite direction to separate the couplings. Moreover, the couplings may only be joined together along a common longitudinal axis to form a joint when such locking assemblies are in an armed position which automatically occurs upon each disconnection of the couplings, and such couplings are prevented by their design by being co-joined in an incorrect fashion.